There are a number of applications where it is desirable to remove air from a storage container when storing an item. One example is food storage, where, to prevent food from spoiling while stored, air is pumped out of the container. A number of devices are offered for sale that provide a vacuum sealed bag. In some vacuum seal systems, food is placed in an open plastic bag, and the open end of the bag is placed in sealing pump device which pumps air out of the bag, and then thermally seals the bag. In other arrangements, a valve device is mounted on the bag which allows air to be pumped out of the bag once the bag is closed. Another food-related application of vacuum sealing is marinating food items. The vacuum allows ambient air pressure to urge liquids surrounding the food item in the bag into the food item to affect flavor of the food item. Still another popular usage of vacuum sealed food items is in “sous vide” cooking, where the food, vacuum sealed in its bag, is placed in heated water to raise the temperature of the food item to the temperature of the water. Sous vide cooking has recently gained in popularity, and while it was initially limited to commercial restaurant cooking, home appliances known as immersion circulators have become popular for facilitating sous vide cooking at home.
However, several problems can occur with food vacuum seal systems. For one, since a pump is used to create a vacuum to draw air out of the bag, it can also draw out liquids that may be present in the bag, particularly in marinating usages. Therefore the pump needs to be designed to accommodate liquids without fouling the mechanism and causing failures. Another problem that can occur is that the food can form a seal against the inside of the bag, potentially trapping air such that air pockets remain in the bag even after the pump has reached maximum vacuum. This defeats the purpose of a “vacuum seal” storage container, which is intended to remove virtually all air, or as much as possible, from around the food. Also, there is the cost of the pump device itself, which tends to be prohibitive, and if it could be avoided, would allow people to vacuum seal food far less expensively. In general the prior art systems rely on an electrically powered pump, which either requires batteries or a commercial electrical outlet to operate. Thus, the usability of a pump is dependent on a power source.
Therefore, a need exists to overcome the problems with the prior art as discussed above.